Submission #1106348

#	Time	Username	Problem	Language	Result	Execution time	Memory
1106348		Zero_OP	Cities (BOI16_cities)	C++14	100 / 100	5810 ms	173052 KiB

cities

#include <bits/stdc++.h>

using namespace std;

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        } return false;
    }

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int N, K, M;
    cin >> N >> K >> M;
    vector<int> cities(K);
    for(int i = 0; i < K; ++i){
        cin >> cities[i];
        --cities[i];
    }

    vector<vector<pair<int, int>>> adj(N);
    while(M--){
        int u, v, w;
        cin >> u >> v >> w;
        --u, --v;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }

    const long long inf = 1e18;
    using node = tuple<long long, int, int>;
    priority_queue<node, vector<node>, greater<node>> pq;
    vector<vector<long long>>  d(1 << K, vector<long long>(N, inf));
    vector<vector<bool>> visited(1 << K, vector<bool>(N, false));

    for(int i = 0; i < K; ++i){
        d[1 << i][cities[i]] = 0;
        pq.push({d[1 << i][cities[i]], 1 << i, cities[i]});
    }

    int full = (1 << K) - 1;
    while(!pq.empty()){
        long long cur; int mask, u;
        tie(cur, mask, u) = pq.top(); pq.pop();

        if(visited[mask][u]) continue;
        visited[mask][u] = true;

        for(auto [v, w] : adj[u]){
            if(minimize(d[mask][v], d[mask][u] + w)){
                pq.push({d[mask][v], mask, v});
            }

            int not_mask = mask ^ full;
            for(int s = not_mask; s > 0; s = (s - 1) & not_mask){
                if(minimize(d[mask | s][v], d[mask][u] + d[s][v] + w)){
                    pq.push({d[mask | s][v], mask | s, v});
                }
            }
        }
    }

    long long ans = inf;
    for(int i = 0; i < N; ++i){
        minimize(ans, d[(1 << K) - 1][i]);
    }
    cout << ans << '\n';

    return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:52:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   52 |         for(auto [v, w] : adj[u]){
      |                  ^

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26